How to: Cast a tarantula (or any object) in resin

[Jojos]

I hope you will show us your test Joe?

 

[xhexdx]

That was impressive. :clap:

Nice weather you got there btw -.-

It's still a little cool for my standards...I grew up in Hawaii.

Jojos, yeah, when I get a testin', I'll post results. Gotta focus on replacing the front door to the house first.

--Joe

 

[Neophyte]

-11F here -.-

 

[xhexdx]

-11F here -.-

It's somewhere in the sixties right now I think.

 

[Neophyte]

:wall:

It's somewhere in the sixties right now I think.

*envy*
I had to bring my G. Rosea to someone so they can mate him today. It was so cold out and I couldn't stop repeating 'sorry' to the poor thing. :wall:

He's somewhere warm now though =)

 

[Jojos]

It's still a little cool for my standards...I grew up in Hawaii.

Jojos, yeah, when I get a testin', I'll post results. Gotta focus on replacing the front door to the house first.

--Joe

LOL! I hope so... Here it's very cold so you can bet that all my doors work very well.

 

[Stan Schultz]

Joe and All -

... An honor to have you post on my thread, Mr. and Mrs. Schultz. ...

Stan and Marguerite, please. No need to get so stuffy.

... I wonder why they wouldn't just use 100% alcohol right away? I'm sure there is some reason....

It has something to do with the strong alcohol tanning the exoskeleton and preventing further water exchange, I think. Thus, you start out with relatively mild alcohol, changing it daily, and gradually work your way to the 100% stuff to extract every last bit of water. It's a long, arduous process. I'd have a lot of trouble completing the job. I'm too impatient!

... It's been my experience with perserving animals in alcohol (I have a bat, a mole, a slipper lobster, a squid, among other things), that they too alter their coloration after time...

Most biological pigments are sensitive to light. They degrade with time as they're exposed to light. They also oxidize or otherwise degrade with time because they're slightly unstable and sensitive to just about any reactive compounds. Degrading biological tissues as well as most preservatives are loaded with reactive compounds. That's why almost all biological specimens in museums are all but worthless for DNA analysis. Though not a pigment, DNA is just as sensitive, maybe more so. It's the same principle.

In living organisms the degraded pigments are constantly replaced with freshly manufactured stuff. Not so in a pickled specimen. Virtually every museum specimen on the planet is a melange of different shades of tan through brown to black because melanin is one of the few biological pigments that doesn't degrade readily. That's also why coloring is rarely used in identifying biological specimens by the professionals. (Patterns, on the other hand, are sometimes used.)

BTW, I found the reference for that booklet:

Hardin, Cleo E. 1963. How to Preserve Animal and Other Specimens in Clear Plastic. Naturegraph Publishers. Happy Camp, Calif.

You can get copies through amazon.com at http://www.amazon.com/Preserve-Anim...=sr_1_5?ie=UTF8&s=books&qid=1233537852&sr=1-5 and they're fairly inexpensive.

Keep up the good work and keep us informed. (Hint: Append your further comments to this thread - even months down the road - so we can keep track of the history.)

 

[Stan Schultz]

well i have heard soaking a T in alcohol ruins it...

Soaking a live tarantula in alcohol ruins it, but you already knew that. I'm just being a $m@rt***. Sorry.

Soaking a dead tarantula in alcohol washes away the wax layer from the surface of its exoskeleton and mats the bristles. When they dry out they look terrible. However, if you keep them under the surface of the alcohol they look almost alive until their colors begin to fade.

In the case of mounting them in plastic, this doesn't matter because the tarantula ordinarily goes from an alcohol solution to a resin solution without drying out enough to mess up the bristles.

 

[Stan Schultz]

... I would use a hand held vibrating sander next to the mold if I didn't have a vacuum chamber. But I would only use to shake loose the trapped air and then turn it off and let it set to cure.

Or merely set the dish carefully on the hood of a running car. There's almost surely a wide spectrum of vibrations that would work, and the gentle thrumming of an idling engine would probably work just fine.

 

[Talkenlate04]

Or merely set the dish carefully on the hood of a running car. There's almost surely a wide spectrum of vibrations that would work, and the gentle thrumming of an idling engine would probably work just fine.

Guiding the bigger bubbles out to the surface with a chopstick works very well also.

 

[xhexdx]

I'll be sure to try multiple methods if/when I cast more.

 

[Jojos]

Joe and All -



Stan and Marguerite, please. No need to get so stuffy.



It has something to do with the strong alcohol tanning the exoskeleton and preventing further water exchange, I think. Thus, you start out with relatively mild alcohol, changing it daily, and gradually work your way to the 100% stuff to extract every last bit of water. It's a long, arduous process. I'd have a lot of trouble completing the job. I'm too impatient!



Most biological pigments are sensitive to light. They degrade with time as they're exposed to light. They also oxidize or otherwise degrade with time because they're slightly unstable and sensitive to just about any reactive compounds. Degrading biological tissues as well as most preservatives are loaded with reactive compounds. That's why almost all biological specimens in museums are all but worthless for DNA analysis. Though not a pigment, DNA is just as sensitive, maybe more so. It's the same principle.

In living organisms the degraded pigments are constantly replaced with freshly manufactured stuff. Not so in a pickled specimen. Virtually every museum specimen on the planet is a melange of different shades of tan through brown to black because melanin is one of the few biological pigments that doesn't degrade readily. That's also why coloring is rarely used in identifying biological specimens by the professionals. (Patterns, on the other hand, are sometimes used.)

BTW, I found the reference for that booklet:

Hardin, Cleo E. 1963. How to Preserve Animal and Other Specimens in Clear Plastic. Naturegraph Publishers. Happy Camp, Calif.

You can get copies through amazon.com at http://www.amazon.com/Preserve-Anim...=sr_1_5?ie=UTF8&s=books&qid=1233537852&sr=1-5 and they're fairly inexpensive.

Keep up the good work and keep us informed. (Hint: Append your further comments to this thread - even months down the road - so we can keep track of the history.)

Thank you very much for all that information. :worship:

 

[xhexdx]

BTW, I found the reference for that booklet:

Hardin, Cleo E. 1963. How to Preserve Animal and Other Specimens in Clear Plastic. Naturegraph Publishers. Happy Camp, Calif.

I don't mean to knock that booklet, but it was published in 1963? I wonder if there are any more recent publications with updated methods.

I still think I'll pick this one up though. Thanks again for the info.

--Joe

 

[DrAce]

Seems I'm a latecomer to the thread. I think it's certainly worthy of 'sticky' status!

...
No, I did not do anything to remove the water from the carcass first. I was not sure how to preserve the carcass long enough post-mortem without freezing, so I bought what I needed and just went for it. I wonder why they wouldn't just use 100% alcohol right away? I'm sure there is some reason.

It's been my experience with perserving animals in alcohol (I have a bat, a mole, a slipper lobster, a squid, among other things), that they too alter their coloration after time. Whether it was hours or weeks or months, I couldn't tell you, but I have seen the color change. It may be worth a small experiment though with some more common animals (we have tons of anoles around here.

With regards to the water rotting inside the carcass and seeping through the resin, I suppose that's a possibility (similar to osmosis?), and I have no choice now but to wait and see what happens.
...

You got kinda the answer which I'll re-state here:

...
It has something to do with the strong alcohol tanning the exoskeleton and preventing further water exchange, I think. Thus, you start out with relatively mild alcohol, changing it daily, and gradually work your way to the 100% stuff to extract every last bit of water. It's a long, arduous process. I'd have a lot of trouble completing the job. I'm too impatient!

And that's basically the story. Ethyl alcohol (particularly 100% - which is practically impossible to get) is a very potent absorber of water (hygroscopic is the magic term). If you add it to larger objects, you run the risk of just sucking all the water out of them as you would if you stuck them in a heat-dessicator.

We use the 70-100% ethanol trick when we prepare histology slides. If you dump them immediately in 100%, you'll actually see all the cells shrink, and structures move away from each other.

Jumps of 10% are fine, so 70%, then 80%, then 90%, and finally 100% (in a sealed container, since 100% ethanol will suck water from air quite rapidly).
I would also get the 100% ethanol as soon as possible to when you need it, for the same reasons I mention above.

...
Most biological pigments are sensitive to light. They degrade with time as they're exposed to light. They also oxidize or otherwise degrade with time because they're slightly unstable and sensitive to just about any reactive compounds. Degrading biological tissues as well as most preservatives are loaded with reactive compounds. That's why almost all biological specimens in museums are all but worthless for DNA analysis. Though not a pigment, DNA is just as sensitive, maybe more so. It's the same principle.

In living organisms the degraded pigments are constantly replaced with freshly manufactured stuff. Not so in a pickled specimen. Virtually every museum specimen on the planet is a melange of different shades of tan through brown to black because melanin is one of the few biological pigments that doesn't degrade readily. That's also why coloring is rarely used in identifying biological specimens by the professionals. (Patterns, on the other hand, are sometimes used.)
...

By definition, all pigments are interacting with light. Each time this happens, you get a slightly increased chance that you'll break the molecules (technically, this often occurs from transfer of electrons out of pi-orbitals, where they then have the chance to jump onto something like water nearby).

Alcohol particularly destroys colour because it happens to be good at taking both water soluble and fat soluble pigments, and because it can also react with some of them.

There are matrixes (that's fancy talk for resins) which can reduce the loss of colour. Epoxy isn't one of them, partly because it's created by the use of radical-polymerisation, which uses fairly reactive starting materials (the initiating factor is quite reactive).

 

[DrAce]

... That's why almost all biological specimens in museums are all but worthless for DNA analysis. Though not a pigment, DNA is just as sensitive, maybe more so. It's the same principle.

...

That, and they're mostly stored in formalin... which binds up DNA and proteins and all sorts and makes it practically useless.

 

[xhexdx]

I was hoping you would post here, DrAce. Thanks.

Great info, too. Gotta love the technical stuff.

 

[DrAce]

I was hoping you would post here, DrAce. Thanks.

Great info, too. Gotta love the technical stuff.

You are, as always, most welcome.

 

[mutley100]

Great thread guys and gals . I was just wondering how easy it would be to preserve sheds last week . Just 1 thing , can someone do a 'Dehydrating and Casting for beginners' as the bit on dehydrating gave me a headache .

 

[bamato]

Or merely set the dish carefully on the hood of a running car. There's almost surely a wide spectrum of vibrations that would work, and the gentle thrumming of an idling engine would probably work just fine.

Is it possible the heat from the engine would hinder or assist in the resin setting?

This has been a great thread by the way. :clap:

And to clarify, you poured the resin in layers for what reason? Is this because of the heat issue? Does it effect the setting process?

 

[JDeRosa]

I found this other thread from a couple years back discussing the same thing, but a slightly different method. The author claims that his T's from 40 years ago are still vibrant and haven't lost color.

It seems that the main differences are that he let the freezer dry out the T, then just brushed a thin layer of alcohol on and let it evaporate. Then patted it dry.

http://www.arachnoboards.com/ab/showthread.php?p=833193#post833193